Inkjet printers use a printhead that includes an array of orifices through which ink is ejected on to paper or other print media. Ink filled channels, supplied from a reservoir, feed ink to a firing chamber at each orifice. In a piezoelectric type inkjet printhead, the deformation of a piezoelectric element coupled to one wall of the firing chamber alternately contracts and expands the volume of the firing chamber. During contraction, pressure in the chamber increases and ink is expelled from the chamber through the orifice. During expansion, pressure in the chamber decreases and ink refills the chamber through the channels from the reservoir(s), allowing for repetition of the ink expulsion sequence. One challenge in designing printheads with more dense orifice arrays and correspondingly smaller firing chamber dimension(s) is generating sufficient pressure differentials within the chamber volume to sustain adequate ink expulsion and refill. Thus, it may be desirable in some printhead designs to maximize the volume change in the firing chamber achieved by each deformation of the piezoelectric elements.